This invention concerns improvements in and relating to polyester fiber filling material, commonly referred to as polyester fiberfill, and more particularly to improvements in the resistance to burning of such material and of articles, such as batts, quilted composites, fabrics, garments and other articles made therefrom.
Polyester fiberfill is used commercially in many garments and other articles, such as sleeping bags, comforters and pillows. A particularly useful and desirable form of polyester fiberfill has a coating of cured polysiloxane, e.g. as disclosed in Hofmann U.S. Pat. No. 3,271,189 and Mead et al. U.S. Pat. No. 3,454,422, because certain desirable properties, such as bulk stability and fluffability are improved thereby. Most polyester fiberfill has been in the form of staple fibers, but, more recently, tows of continuous filaments have been proposed and used, e.g. as described by V. Altvatter in Chemiefasern/Textil Ind. 23 (February 1973), 117-118. Some polyester fiberfill products are used in the form of a resin-bonded batt, as mentioned by P. J. Kline in Textile Chemist and Colorist, Volume 8 (1976), pages 35-37. The resin bonding agent is sprayed onto the fiberfill, e.g. in the form of batts of staple fibers, and provides an advantageous means of increasing the cohesion of the batts. These resin-bonded polyester batts, containing relatively small amounts of cured resin (generally less than 20% by weight) are to be contrasted with impregnated fiber batts containing much more resin, e.g. for use as artificial leather.
T. J. Swihart and P. E. Campbell have reported that silicone coatings increase the flammability of polyester filamentary materials in an article entitled "How Silicones Affect Fabric Flammability", in Textile Chemist and Colorist, Volume 6 (1974) pages 109-112. Similarly, P. J. Kline has reported that resin-bonding increases the flammability of polyester fiberfill. The object of the present invention has been to reduce the horizontal burning rate of such polyester fiberfill when subjected to a small flame (such as a candle or burning twig, to which articles such as sleeping bags may be exposed), without losing the desirable properties brought about by the use of the polysiloxane coating and/or the resin bonding agent.
A recent suggestion for improving the flame-resistance of polyester fiberfill has been to coat or bond a mixture of 65 to 95% polyester and 5 to 35% of non-flammable halogen-containing polymer with a specific non-flammable halogen-containing copolymer containing up to 10% of flame-retardant halogen-containing synergist in Hurwitz U.S. Pat. No. 3,870,590 (also reported by P. J. Kline). Hurwitz warns against the use of large amounts of halogen-containing polymers in fiberfill because of the severe loss of resilience and the tendency to pack down in use. He notes that, although expensive flameproof fibers are available and have been blended with flammable fibers in an attempt to obtain less expensive textile products having non-flammable properties, the products obtained from such a mixture of polyester fibers still have deficiencies making them unsuitable for many uses if the proportion of non-flammable fibers content is high enough to make the product self-extinguishing.
Generally, the addition of small amounts of flame-resistant fibers to batts of polyester staple fibers (that have not been coated with silicone or resin-bonded) has increased the horizontal burning rate of the batts.
It was very surprising, therefore, to find that a significant reduction in the horizontal burning rate of polysiloxane-coated and/or resin-bonded polyester fiberfill could be achieved without significant loss of desirable characteristics merely by incorporating relatively small amounts of certain other filamentary materials.